The present invention relates generally to hand-held, manually-operated sanding tools for use with a replaceable sheet of abrasive material such as sandpaper. More particularly, it relates to sanding tools adapted to satisfy user handling preferences.
Abrasive sheets, such as conventional sandpaper, are commonly used to hand-sand or finish a work surface, such as a wooden surface. With hand-sanding, the user holds the sandpaper directly in his/her hand and then moves the sandpaper across the work surface. Sanding by hand can, of course, be an arduous task. To facilitate the hand-sanding process, the sandpaper can instead be retained by a sanding block or tool sized to fit within the user's hand. The sanding block or tool thus makes hand-sanding faster and easier. One example of a commercially-available sanding block is the 3M™ Rubber Sanding Block available from 3M Company of Saint Paul, Minn.
U.S. Pat. No. 5,168,672 describes another exemplary sanding block or tool in the form of an abrasive sheet holder having a base provided with clamping shoulders formed in a pair of opposed side edges thereof. A handle is detachably secured over a rear surface of the base. The handle has opposed flexible flange walls for clamping opposed end edge portions of an abrasive paper sheet that is otherwise positioned over a front working surface of the base, with the edge portions of the paper sheet extending over the clamping shoulders. A grip portion of the handle promotes grasping thereof within a palm of the user's hand. The grip portion is spatially fixed relative to the base. Thus, the grip portion is also spatially fixed relative to paper attached to the base.
Additionally, U.S. Patent Application Publication No. 2003/0104777 describes a sanding block or tool including a generally rectangular base housing upon which a multi-contoured, generally convex hand-grip is secured. The hand-grip further defines inwardly extending concave portions that facilitate easy and secure grasping by the user. Further, an over-center lever clamp mechanism is operative at each end of the sanding block to secure the opposed ends of a sandpaper sheet in a releasable manner. The hand-grip is ergonomic in design, and is spatially fixed relative to the base (and thus relative to sandpaper secured to the base).
As highlighted by the above, while well-accepted, known sanding blocks may have certain shortcomings. For example, it is desirable that the sanding block promote sanding in multiple directions such that the sheet of abrasive material will wear relatively evenly. This desired characteristic, in turn, means that most of the available abrasive material surface area is used before the sheet is discarded. Unfortunately, the spatially fixed handles associated with known sanding blocks do not satisfy this user preference. To the contrary, while the grip portion of known sanding block handles provide a “natural” directional orientation of the user's hand when grasping the grip portion, this directional orientation of the grip portion/user's hand relative to the abrasive material retained by the tool cannot be altered. This, in turn, dictates that sanding will primarily occur in only one or two sanding directions. In other words, the fixed grip portion promotes sanding in either an up-and-down direction or a left-to-right direction relative to the user's hand; these limited sanding directions may result in uneven wear of the abrasive material. Further, the unidirectional configuration of the known sanding block grip portion may cause distinct user discomfort over periods of extended use, such as where the natural directional orientation is contrary to the user's desired hand orientation or where the user desires to sand in multiple different directions. These concerns arise with flexible flat sheets of abrasive material, such as conventional sandpaper, as well as with resilient flexible abrasive sheets that are thicker than conventional sandpaper, such as the sheet-like abrasive materials described in, for example, Minick et al., U.S. Pat. No. 6,613,113.
U.S. Pat. No. 6,524,175 describes a pole sanding tool having a head maintaining a layer of hook-and-loop fastening material for attachment to a corresponding surface of a sanding sponge. The pole sander head further includes a universal joint for receiving an end of an elongated pole. Though pole sanding tools represent a distinct field apart from that of hand-held sanding tools, the universal joint may facilitate “swiveling” of the pole relative to the head. However, because the pole itself does not include a discernable grip portion or desired grasping orientation, the universal joint does not address rotation of a grip portion relative to the head, nor does it “lock” the pole relative to the head at multiple rotational orientations.
In light of the above, a need exists for a hand-held sanding tool that is easy to consistently load with an abrasive sheet and that provides multiple rotational orientations of a handle relative to the retained abrasive sheet to enhance user comfort.